In the push for ever smaller microelectronic devices, researchers have constantly sought to reduce the size of charge carriers in such devices. The ultimate miniaturization of devices is achieved when charge carriers reach the atomic scale. One material of interest for use in reducing the size of such devices is graphene.
Graphene is a single atomic sheet of graphitic carbon atoms that are arranged into a honeycomb lattice. It can be viewed as a giant two-dimensional Fullerene molecule, an unrolled single wall carbon nanotube, or simply a single layer of lamellar graphite crystal. Electron mobility values as high as 200,000 cm2/Vs at room temperature have been measured (Morozov et al, PRL 10, 016602, 2008) making this material extremely attractive for microelectronic applications. However, the transport properties of graphene are very sensitive to modifications of its electronic structure brought about by adsorbates, defects and impurities in the crystal lattice. The challenges of constructing a device using graphene in a manner that can maintain its excellent transport properties are so great that no practical device has been produced using graphene. Therefore, the vast potential of this material has yet to be fully realized.